#!/bin/bash
#
# A simple script to create and rebuild partial debian test mirrors
# suitable for testing the debian installer.
#
# This script does _no_ proper updating of the partial mirror, it
# just accumulates the packages and creates an apt-getable archive
# structure for them.
#
# The following variables are intended for customization:
#
# MIRROR: The mirror URL to download from. E.g. "http://localhost/debian"
#         If not set, the script will only rebuild the archive
#         metainformation for the packages already available.
#
# SUITE: The suite to mirror, e.g. "testing". Defaults to "unstable".
#
# DIST: The distribution's code name. If not set, it tries to guess one
#       based on SUITE.
#
# ARCH: The architecture to mirror. This can only be a single value.
#
# TARGET: The root directory of the partial mirror to build. Defaults
#         to the current directory.

#
# useful shell functions
#
download ()
{
	_wget="wget -nc -q"

	mkdir -p $_target

	$_wget -P $_workdir $_mirror/dists/$_dist/main/binary-$_arch/Packages.gz
	gzip -cd $_workdir/Packages.gz |grep '^Filename: ' |sed 's/^Filename: //' >$_workdir/deblist
	rm $_workdir/Packages.gz
	$_wget -P $_workdir $_mirror/dists/$_dist/main/debian-installer/binary-$_arch/Packages.gz
	gzip -cd $_workdir/Packages.gz |grep '^Filename: ' |sed 's/^Filename: //' >$_workdir/udeblist
	rm $_workdir/Packages.gz

	# We mindlessly grab every available .udeb
	for i in $(<$_workdir/udeblist); do
		$_wget -P $_target $_mirror/$i
	done

	for i in $(debootstrap --keep-debootstrap-dir --print-debs --arch $_arch $_dist $_workdir); do
		_file=$(grep "/${i}_.*_\(all\|${_arch}\)\.deb$" $_workdir/deblist)
		$_wget -P $_target $_mirror/$_file
	done

	# Don't miss the kernel, bootloaders, and initrd tools if necessary
	# FIXME: Definitions for more architectures
	case $_arch in
		alpha) echo "Extra packages unknown"; exit 1 ;;
		amd64) echo "Extra packages unknown"; exit 1 ;;
		arm) echo "Extra packages unknown"; exit 1 ;;
		hppa) echo "Extra packages unknown"; exit 1 ;;
		i386) extra="kernel-image-2.4-latest kernel-image-2.6-latest lilo grub initrd-tools" ;;
		ia64) echo "Extra packages unknown"; exit 1 ;;
		m68k) echo "Extra packages unknown"; exit 1 ;;
		mips) extra="kernel-image-2.4.27-r4k-ip22 kernel-image-2.4.27-r5k-ip22 kernel-image-2.4.27-sb1-swarm-bn arcboot dvhtool file libmagic1 sibyl" ;;
		mipsel) extra="kernel-image-2.4.27-r5k-cobalt kernel-image-2.4.27-sb1-swarm-bn sibyl colo" ;;
		powerpc) echo "Extra packages unknown"; exit 1 ;;
		s390) echo "Extra packages unknown"; exit 1 ;;
		sparc) echo "Extra packages unknown"; exit 1 ;;
		*) echo "Unknown architecture"; exit 1 ;;
	esac
	for i in $extra; do
		_file=$(grep "/${i}_.*_\(all\|${_arch}\)\.deb$" $_workdir/deblist)
		$_wget -P $_target $_mirror/$_file
	done
}

rescan ()
{
	_tdist="$_target/dists/$_suite/main"
	_debpkg="$_tdist/binary-$_arch/Packages"
	_udebpkg="$_tdist/debian-installer/binary-$_arch/Packages"

	mkdir -p $_tdist $_tdist/binary-$_arch $_tdist/debian-installer/binary-$_arch
	(cd $_target/dists && rm -f $_dist && ln -s $_suite $_dist)

	dpkg-scanpackages $_target /dev/null >$_debpkg
	gzip -c $_debpkg >${_debpkg}.gz
	dpkg-scanpackages -u $_target /dev/null >$_udebpkg
	gzip -c $_udebpkg >${_udebpkg}.gz

	_debmd5sum=$(md5sum $_debpkg |cut -d' ' -f 1)
	_debsize=$(find $_debpkg -printf %s )
	_udebmd5sum=$(md5sum $_udebpkg |cut -d' ' -f 1)
	_udebsize=$(find $_udebpkg -printf %s )

	cat >$_target/dists/$_suite/Release <<- EOF
	Origin: Debian
	Label: Debian
	Suite: $_suite
	Codename: $_dist
	Date: $(date -R)
	Architectures: $_arch
	Components: main
	Description: Debian Test Mirror - Not Released
	MD5Sum:
	 ${_debmd5sum}            ${_debsize} main/binary-$_arch/Packages
	 ${_udebmd5sum}            ${_udebsize} main/debian-installer/binary-$_arch/Packages
	EOF
}

cleanup ()
{
	rm -rf ${_workdir}
}

#
# set some variables used in the shell functions
#
set -e

_workdir=$(mktemp -d)
trap cleanup EXIT

_mirror=$MIRROR
_suite=${SUITE:-"unstable"}
if [ -n "$DIST" ]; then
	_dist=$DIST;
	case $_dist in
		lenny) _suite="stable" ;;
		squeeze) _suite="testing" ;;
		sid | *) _suite="unstable" ;;
	esac
else
	case $_suite in
		stable) _dist="lenny" ;;
		testing) _dist="squeeze" ;;
		unstable | *) _dist="sid" ;;
	esac
fi
_arch=${ARCH:-$(dpkg --print-architecture)}
_target=${TARGET:-"."}

#
# do the work
#
[ -z "$_mirror" ] || download
rescan